Process of making low-boiling hydrocarbons from petroleum or other oils



Patented Aug; 31, 1926.

JGSEFI-I HIlDY JAMES, OF PITTSBURGH, PENNSYLVANIA, ASSIG'NOR TO CLARENCE P.

BYBNES, TRUSTEE, OESEWICKLEY, PENNSYLVANIA.

PRQGESS F EIAKING LOWIBOILING HYDROCARBOES FRQM PETRQLEUM 03 OTHER i GILS.

N0 Drawing.

tion, or the products of low temperature distillation of coal, or their distillates.

In said process, hydrocarbons are Vaporized, mixed with air or oxygen-containing gas in regulated proportions near the the oretical combining proportion, and preferably in excess thereof; and the mixture is passed, with or Without the addition of a diluting gas, such as steam, through a layer or successive layers of catalytic material under a regulated temperature below a red heat. The catalysts employed are preferably complex oxides or compounds of metals having a varying valence, such for example, as blue oxides ofmolybdenum or the oxides 2 of vanadium or uranium. The products of this method are then condensed, giving a mixture of partial oxidation products, usually ranging from alcohols through aldehydes to aldehyde fatty acids. The proc- 0 ess may be varied to produce a greater or less proportion of the aldehyde fatty acids and a greater or less proportion of the aldehydes. Such process is disclosed in my copending application, Serial No. 272,567, filed January22, 1919.

I have discovered on further experimen" tation that these compounds, which can be very easily and cheaply prepared by partialoxidation or partial combustion moth ods described in my pending applications,

Application filed November 13, 1919. Serial No. 335727 05.

tion also usually resulting in a breaking inv two of the hydrocarbon chains. V In carrying out my method, I preferably subjectthe vapors of the mixture to a tem d0 perature above 450 (3., usually combined with steam, and preferably subject the steam vapor mixture to the action of contact material. s i

The contact substances which Iprefer in carrying out the process are metals of low atomic volume, such as nickel, copperor iron. lVhen using steam, for example, at the temperatures best suited for these reactions, metals such asiron are partly oxidized by the steam, with their formation of hydrogen. However, this reaction is reversible so that there is always enou hmetal present to act as a catalyst. In addltion the hydrogen formed reacts with the olefins formed, to change them into saturated. hydrocarbons. Under this treatment, part of the partial oxidation products break down, probably. in accordance with, the following equations:

Aldehyde acid wax.

v Hydrocarbon.

Carbon monoxide.

Dialdeliyde.

With the aldehyde acids, waxes and dial- Hydrocarbon.

. dehydesthe above decompositions can also be accompanied (where the molecular weight is high) by a simultaneousbreaklng in two of the hydrocarbon chain. For ex ample:

oon, uo heated o,H +G11 1,.+oo +00,

1 on I C Aldehyde acid. Heptylene.

-With aliphatic alcohols the following decomposition takes place:

- Aliphatic alcohol.

And with an aldehyde alcohol the following:

- Inactual practice the decompositions proceed t0 some-extent further than I have indicated above, as I always obtain certain hydrocarbons, particularly olefins in the gas mixtures formed.

I wish also to note that the above decompositions actually take place to a certain extent at the time of the oxidation process itself, This is due-to the fact that the above compounds are necessarily subjected to a high temperature at the moment of formation.

This decomposition, which takes place'to some extent at the time of the partial oxidation process, can be increased in several different wa s. For example, the depth of the heat. through an electric grid or otherwise,

this heatbein applied either between the screens or in t e second screen;

In th1s way and varlous other ways,'I'

may thus greatly increase-the amount of lowmolecular-weight hydrocarbons obtained in the original process. v

I have also found by extended experl menting that I can obtain better results in producing lower boiling point hydrocarbons in this manner b using, in addition to the contact metals a ove noted, a basic oxide,

preferably magnesium oxide. In the presence of steam, the aldehyde acids react with this oxide to form-corresponding magnesium salts. As I preferably carry out the reaction above 450 (3., these salts probably exist only momentarily and are probably at once broken into ketones; the ketones in turn being probably broken down (aided by the catalytic activity of the metal or metals present) to carbon monoxide and hydrocarbons .of lower molecular weight than the bodies introduced in the process. It should be noted that the steam in con'unction with the basic oxide brings about t e saponification of the waxes present, the aldehyde fatty acids thus liberated undergoing the decompositions as outlined above. i

- j The foregoingactions of the basic oxide mayprobably be illustratedby the follow Ketone. Olefin hydrocarbon.

Where magnesium oxide is used, for example, as the contact material, I believe that the aldehyde acids are converted into salts, and these salts decomposed with removal of carbon.

I may use metals or basicoxides, or mixtures of both, at a high decomposition temperature. If basic oxides are used, I preterably use those whose carbonates decompose at the temperature employed.

of any molecular welght T can step down I a part of the partial combustion products thereof to hydrocarbons of lower or less molecular weight; and by repeating the operation I can'again produce hydrocarbons of still lower molecular weight.

My experiments show that on passing a It will be noted that on the whole there is a more rapid elimination of carbon on the second assage through the process, due to this ole n oxidation and subsequent decomposition.

I willnow describe certain examples of the complete process:

1. The raw material kerosene, hownin the market as Pittsburgh lamp oil, gave the following results on lEngler distillation:

Percent.

Below 200 C 0.0

' Below 260 C 46.0 Below 300 C 54.0

In the first step the oil was subjected to the partial oxidation process of-my co-pending applications under the following condi tions:

Temperature of the catalyst above 320 C. p Air ieed300 cubic ieetper hour.

Oil feed9.5 liters per hour.

vee

given partial combustion product mixturethrough the' process, the breaking down action takes place to even a greater degree than that outined in the above theory. For example, starting with kerosene and .subjecting it to the partial combustion process,

and then to the present process, I obtain in.

addition to the gasolene content some gaseous hydrocarbons; and starting with gas oil in a similarway, in addition to the kerosene content, I obtain a certain amount of gasolene and some gaseous hydrocarbons. Thus, starting with a petroleum distillate, the vapor of the petroleum distillate mixed with.

air will be subjected to the partial combustion or the partial oxidation process of my copending applications. As stated above, there will be some incidental decompositionof the products in this process itself. The volatile orslow molecular weight hydrocarbons formed in such process ma be distilledvofi', and if desired the partial oxidation process may be repeated to increasev the content of aldehyde fatty acids and other intermediate oxidation pro'ducts. .Now, if the remaining heavy hydrocarbons are again passed through the original partial oxida tion process, the reactions are substantially the same as with the original process, with one exception. The heavier olefin hydrocarbons form to some extent as a result of decomposition of the present process, and

these on oxidation in the original process the oxygen react in a different manner, attacking the double bond, breaking the open chain at that point, as shown in the following equation: 1

. O 0. woosmt Diameter of circular catalytic screen-15 inches.

Thickness of catalytic screen-1 centimeter.

The product obtained was 86.8%

volume or the oil fedshowing the following on Engler distillation: I

- Per cent,

Below 100 o 1.0 Below 150 c -4 e0 Below 200 0 14.0

In the second step this oxidation product was subjected to thermal treatment in the presence of magnesium carbonate, in a fur-- nace of 6" diameter, the layer of magnesium carbonate being 2'.

oxidation product was ratus at the rate of 80 cubic centimeters per hour. .No steam was used and the temperature of the magnesium carbonate was about 495 C. The total amount of oil feed was thick. The partialv fed into the appar liu.

-'cubic'centimeters, the amount recovered 112 cubic centimeters,.giving a yield of 56%..

' "On Engler distillation, this product showed the following v Percent. Below 100 C 8 Below 150 C 28 Below 200 C; 64

The gas formed in' the process showed the following:

L Percent. -Carbondioxide 3, I Illuminants 1 35.4 Carbon monoxide c- 20.5

2. Using the sameronditions and material, except that water approximately equal to one-fourth of the oil was added uniformly.

with the oil as fed, I-obtain'the following results with a feed of-85 cubic centimeters.

per hour :-The total amount of oil fed was 300 cubic centimeters, the amount recovered 258 cubic centimeters. giving a yield of 86%.

On Engler distillation the product showed the following:

Below 100 0 4. Below 150 C; 11 Below 200'C 24.5

An'analysis of the gas formed'showed the following: I

- Per cent.

Carbon dioxide c Illuminants i 15.0

Carbon monoxide 8.0

The above distilled products consisted of low molecular weight hydrocarbons, of which olefins were present in amounts varying from 40% to together with some alcohols and aldehydes and aldehyde fatty acids, the latter in amounts up to 5%.- It

should be notcd'that one distillation over alkali or lime will remove the fatty acids, leaving a mixture that is suitable as a substitute for gasolene, as the bodies present" are all combustible and sufiiciently volatile for use as a motor spirit.

In the above experiment, approximately 75% is too heavy to'be used as a motor spirit, and I propose to subject th'eheavy residues tosuch'treatment as is outlined above, modified as desirable by the gradu ally changing character of the mixture.

A In this way I am able, by starting with any hydrocarbon mixture or petroleum frac-. tion, to step it down to any molecular wei ht desired. There are, of course, necessary gas losses, but this will be. more than overcome by the gradually increased value of the'product over'that of the raw material, which maybe distilled fractions of cheap crude oils. I v

I will now describe additionalexperiments showingthe effect of usin metals as catalysts inthe decomposing 'cham er, and also show- Per cent.

ing the results produced when a heavier oil such as gas oil is 'used as the raw material.

3. Using metallic copper as a catalyst with the same partial oxidation product .described in experiments 1 and 2, the-decomposing chamber was filled with a layer of copperized-asbestos and reduced copper oxide 520 C., and the partial oxidation mixture fed in at the rate of 80 cubic centimeters per hour, along with water at the.rate of 20 cubic centimeters per hour. fed was 150 cubic centimeters,,thc oil recovered was 100 cubic centimeters, giving a yield of 66.6%. product showed as follows:

I Per cent, Below 100 C i 4 Below 150 C 15 Below 200 C 32 The gas produced analyzed as follows:

i f Per cent. Carbon dioxide. c 4.5 Illuminants 30 Carbon monoxide 8.5

4. A similar run made with metallic nickel as a catalyst and without using steam gave a recovery of 52%, showing on Engler distillation the following: Y

' V Per cent.

Below 100 C 1.6

Below 150 C 11.6 B low 200 G 25 The gas analyzed asfollows:

Q Percent.

Carbon dioxide 7 Illuminants 5 Carbon monoxide .7

5] A similar run' was made with catalytic iron and iron oxide in the decomposing chamber, using the same amountof water fed as material fed. In this case I obtained a recovery of 77% with-Engler distillation giving the following:

6. With a partial'oxidation, roduct made from gas'oil with an 80% yiel showing on Engler distillation p Per cent.

B'a'ow10o'c- 1.5 Below 150 C 5' Below200" o 171 The total oil scale to a depth of two inches. The tem- .perature was maintained at from 500 to.

On Engler distillation the I subjected .thi's' product'to a thermal effeet with the. decomposing furnace empty, withouta catalyst and using a temperature of 480 to 500 C., feeding the materlal at 90 cubic centimeters per hour with no water. This gave arecovery of about 53.1% showing on-Engler distillation the following:

Percent. Below 100 C 9 Below 150 C Below 200 C 44 The gas analysis showed:

Per cent.

' Carbon dioxide 1 Illuminants 33.5

7 Carbon monoxide 7.4

Below 100 o 7. With conditions the same as example 6, except that one-fourth as much water as partial oxidation product was fed, l[ obtained a recovery of over 95%, showing on Engler distillation the following:.

Per cent.

Below 100 C.

8. lVith the same gas oil partial combustion product as used above, and magnesium carbonate in the decomposing chamber as noted in the kerosene experiments, the following. results were obtained with atomperature of from 500 to 520 C., the material was fed at the rate of 80 cubic centimeters per hour, water at the rate of 20 cubic centimeters per hour, the total amount ofoil mixture fed being 190 cubic cent1- meters, with a recovery of 74.4%. 011 Engler distillation the product showed as follows:

Per cent.

2.5 Below 150 C 11.5 Below 200 C 2.3.

The gas analyzed:

7 Percent. Carbon dioxide 9.8 lllumi'nants 9.9 Carbon monoxide 4.4

9. A further experiment which I made was as follows:

A. heavy gas oil giving no distillatebelow 300 C. was subjected to the partial oxidation process with a double running treatment. Taking the product from the first run and passing it again through the partial combustion apparatus, product thus obtained" contained about l partially oxidizing a the partial oxidation 55.6% of aldehyde fatty acids and showed the following on Engler distillation:

A portion of this product was distilled, setting aside the fraction below 200 C, and the-residuev which amounted to 76% of the original product was subjected to the present thermal decomposition process, but with a catalyzer in the decomposing chamber, consisting of a layer of 2" deep of a mixture of equal parts of magnesium carbonate and finely divided metallic iron (catalytic iron). The run was made at a temperature of 520 to 550 C., with the rateof feed of the double run residue material at 80 cubic centimeters per hour. The water was fed at the rate of 40 cubic centimeters per hour. The total amount of the product fed was 150 cubic centimeterswith a recovery of 76%.

On Engler distillation, the product showed the following:

, -Per cent. Below C 1 Below 150 C 5 Below 200 C 21.5 The gas analysis showed: 7

, I Per cent. Carbon dioxide.- 7.4 l-lluminants 1.4 Carbon m0noxide 7.8

The partial combustion product mixture may be decomposed in other ways than by thermal-decomposition; for example, by subjecting the vapors of the mixture to an oscillating high tension' electric current to break the carbon chain. Many changes may be made in the apparatus used, the steps involved, the materials used, etc.-, without departing from my invention, since I consider myself the first to obtain lower boiling point hydrocarbons from heavier oils through the partial oxidation treatment combined with the thermal decomposition treatment.

ll claim:

1. In the treatment of hydrocarbons which already contain artificially-introduced chemically-combined oxygen, the step consisting of thermally decomposing the same.

2. In the manufacture of lower boiling point. hydrocarbons from higher boiling point. hydrocarbons, the steps consisting of heavier hydrocarbon at a temperature below a red heat to obtain intermediate oxidation products and thereafter thermally decomposing said products.

3. lnthe manufacture of lower boiling point hydrocarbons from higher boiling point hydrocarbons, the steps consisting of partiallyoxidixing the heavier hydrocarbons at a temperature below. a red heat, condensing the resulting vapors to obtain liquid intermediate oxidation products, and then thermally decomposing said products.

4. In the treatment of a hydrocarbon which already con ains artificially-introduced chemically-com ined oxygen, the step consisting'of subjecting said material in the vapor phase to thermal decomposition.

5. In the manufacture'of lower boiling v point hydrocarbons from higher boiling point hydrocarbons, the step consisting of subjecting partially oxidized hydrocarbons the vapor phase to the action of basic oxides.

6. In the manufacture of lower'boiling 'at a temperature below a red heat to obtain intermediate oxidation products, separating a lighter portion of theproduct, and thermally decomposing the heavier portion of the product.

8. In the manufacture of lower boiling point' hydrocarbons from, higher boiling point hydrocarbons, the steps consistingof' partially oxidizing the heavier hydrocarbons at a temperature below a red heat to obtain intermediate oxidation products, thermally decomposing. said product s, separating the lighter portion of the product, and subject-- ing the heavier portion-to an oxidation treatment.

9; In the manufacture of lower boiling point hydrocarbons from higher boiling point hydrocarbons, the steps consisting of partially oxidizing the heavier hydrocarbons in the vapor phase in the presence of oxygen,

condensing the vapor stream mixture, and then decomposing at least .a portion'of the resulting product. A

' 10. In the treatment of hydrocarbons, the steps consisting of partially oxidizing the same while in finely divided condition, separating the lighter portion of the condensed product, subjecting the heavier portion to partial oxidation, and then thermally decomposing the same.

11. In the manufacture of lower boiling point liquid hydrocarbons from higher boil in g point liquid hydrocarbons, the steps coirs'i'stin'g of vaporizing heavier-hydrocarbons,-

mixing the samewith oxygen, passing the mixture over a catalyst, maintaining .the-

catalyst at a temperature below a low red heat, and decomposing a portion of the products to obtain lower boiling point hydro carbons.

12. In the manufacture of lower'boiling point liquid hydrocarbons from-higher'boiling point liquid hydrocarbons, the steps consisting of passing a mixture of heated mineral oil vapor and air through a catalyst at a temperature below a low red heat, and

thermallydecomposing the heavier portion of the'product.

13. In the manufacture of lower boiling point liquid hydrocarbons from higher boiling point liquid hydrocarbons, the steps consisting of passing a mixture ofjheated mineral oil vapor and air through 'a' catalyst at a temperature below a' low red heat, and thermally decomposing the heavier portion .of the product while in vapor form.

In testimony whereof, I have hereunto set my hand.

-' JOSEPH HIDY JAMES. 

